5/31/13

Pay back analysis - General Electric GE GeoSpring

I've been working for some time to reduce my electric bill and concluded that the main driver was my very old (5+ years) water heater. I explored several options for hot water (gas, solar, etc.) and finally concluded that from a payback/ROI standpoint a heat pump based hot water heater was best.

Earlier this week I went ahead with the installation and after only 24 hours I have the first data showing my actual savings.

Rather than waiting until the end of the month, I can now (thanks to the new GMP smart meters), go into my GMP account and see my electricity consumption on an hourly basis - all the way up to this morning.

After signing into my account I was able to export my data into an excel spreadsheet and generate a chart showing my hourly kWh consumption for the past few days - and then compare my "old water heater" usage patterns to my "new water heater" pattern.

The resulting chart looked like this:

Hourly Electric Consumption (click to enlarge)

The blue line was the day before installation the red line was the day of installation and the green line is today. You can see a dramatic decrease in my base level of consumption.

To calculate my ROI on the water heater I calculated my % savings and was astonished to see that I was saving an average of 80%!

Assuming that this continues, in 1 year i was save $1538 - for a total investment of $1500 (not counting the $300 tax incentive).

My payback period? 1 year, maybe less. The official GE website puts my total savings at only $300 per year, but this wasn't taking into consideration the age and efficiency of my very old electric water heater.

My conclusion? Take a hard look at your water heater and then shop around for the most efficient solution you can find - you may be surprised at how much you can save.